What is the story behind it?

Mistletoe's mystical properties stem back to the Celts and Norse people who believed there was something mystical about the plant as the sprigs stayed green in winter even when the tree has lost its leaves.

It was also believed to bring luck in Medieval times.

One Norse tale explains its links to romance, love and kissing.

Balder, son of the goddess Frigga, was killed by an evil spirit with an arrow made of mistletoe.